DE. C. COLLTXGWOOD ON NEW SPECIES OF NUDIBRANCHS. 737 



New Species of Nudibrauchs from the Eastern Seas. 

 By CUTUBERT COLLINGWOOD, M.A., M.B., F.L.S. 



[Read March 7, 1878.] 



(Abstract.) 



The author remarks that collectors searching carefully for these 

 naked-gilled Mollusca within a relatively limited locality are, as 

 a rule, more successful in obtaining them than those who hastily 

 traverse wide areas with but a scanty opportunity at each station. 



He instances Sir AValter Elliott's series from the coast of 

 Madras, and those of Dr. Kelaart at Ceylon, among which new 

 species greatly preponderate over those of the collections obtained 

 by the eminent naturalists accompanying the voyages of the 

 * Astrolabe,' ' Samarang,' &c. 



The habitat of the Nudibranchs under stones is where they are 

 most often found, but few being met with on the surface of the 

 ocean or swimming about nearer shore ; they may, however, be 

 dredged from considerable depths. 



The tropics certainly yield the most numerous species of bril- 

 liant colour ; but on our own coasts there are nevertheless many 

 whose coloration in some respects vies with that of their tropical 

 brethren. 



The geographical distribution of some species is not a little re- 

 markable ; for instance, the British Doris tuberculata is recorded 

 as also to be met with at New Zealand and Vancouver's Island. 

 Dr. Collingwood has himself obtained examples of a species of 

 CJiromodoris from extreme points in the China Seas. 



He relates several instances, showing that Nudibranchiate Mol- 

 lusca are affected by the season and other causes ; for at certain 

 localities where at times they are very abundant, he could not 

 discover a single specimen, spite of the most diligent search. 



Curious cases are also mentioned where self-amputation of the 

 creature's own mantle followed its being imprisoned for a night, 

 the salt water being unchanged. 



The following is a list of the new species described and figured 

 from the living animals, and which will appear in a forthcoming 

 part of the Society's Transactions : — 



Doris pecten. Bush Island, N. Formosa. 



crescentica. China Seas and Borneo. 



Chromodoris iris. Makung, Pescadores Islands. 

 LISJU. JOURN. — ZOOLOGT, VOL. XIY. 55 



